Tests to See How Well Your Dialysis Is Working

About once a month, your dialysis care team will test your blood by using one of two formulas-URR or Kt/V-to see whether your treatments are removing enough wastes. Both tests look at one specific waste product, called blood urea nitrogen (BUN), as an indicator for the overall level of waste products in your system. For more information about these measurements, see the NIDDK fact sheet Hemodialysis Dose and Adequacy.

Conditions Related to Kidney Failure and Their Treatments

Your kidneys do much more than remove wastes and extra fluid. They also make hormones and balance chemicals in your system. When your kidneys stop working, you may have problems with anemia and conditions that affect your bones, nerves, and skin. Some of the more common conditions caused by kidney failure are extreme tiredness, bone problems, joint problems, itching, and "restless legs." Restless legs will keep you awake as you feel them twitching and jumping.

Anemia and Erythropoietin (EPO)

Anemia is a condition in which the volume of red blood cells is low. Red blood cells carry oxygen to cells throughout the body. Without oxygen, cells can't use the energy from food, so someone with anemia may tire easily and look pale. Anemia can also contribute to heart problems.

Anemia is common in people with kidney disease because the kidneys produce the hormone erythropoietin, or EPO, which stimulates the bone marrow to produce red blood cells. Diseased kidneys often don't make enough EPO, and so the bone marrow makes fewer red blood cells. EPO is available commercially and is commonly given to patients on dialysis.

Renal Osteodystrophy

The term "renal" describes things related to the kidneys. Renal osteodystrophy, or bone disease of kidney failure, affects 90 percent of dialysis patients. It causes bones to become thin and weak or formed incorrectly and affects both children and adults. Symptoms can be seen in growing children with kidney disease even before they start dialysis. Older patients and women who have gone through menopause are at greater risk for this disease.

Itching (Pruritus)

Many people treated with hemodialysis complain of itchy skin, which is often worse during or just after treatment. Itching is common even in people who don't have kidney disease; in kidney failure, however, itching can be made worse by wastes in the bloodstream that current dialyzer membranes can't remove from the blood.

The problem can also be related to high levels of parathyroid hormone (PTH). Some people have found dramatic relief after having their parathyroid glands removed. The four parathyroid glands sit on the outer surface of the thyroid gland, which is located on the windpipe in the base of your neck, just above the collarbone. The parathyroid glands help control the levels of calcium and phosphorus in the blood.

A cure for itching that works for everyone has not been found. Phosphate binders seem to help some people; these medications act like sponges to soak up, or bind, phosphorus while it is in the stomach. Others find relief after exposure to ultraviolet light. Still others improve with EPO shots. A few antihistamines (Benadryl, Atarax, Vistaril) have been found to help; also, capsaicin cream applied to the skin may relieve itching by deadening nerve impulses. In any case, taking care of dry skin is important. Applying creams with lanolin or camphor may help.

Sleep Disorders

Patients on dialysis often have insomnia, and some people have a specific problem called the sleep apnea syndrome, which is often signaled by snoring and breaks in snoring. Episodes of apnea are actually breaks in breathing during sleep. Over time, these sleep disturbances can lead to "day-night reversal" (insomnia at night, sleepiness during the day), headache, depression, and decreased alertness. The apnea may be related to the effects of advanced kidney failure on the control of breathing. Treatments that work with people who have sleep apnea, whether they have kidney failure or not, include losing weight, changing sleeping position, and wearing a mask that gently pumps air continuously into the nose (nasal continuous positive airway pressure, or CPAP).

Many people on dialysis have trouble sleeping at night because of aching, uncomfortable, jittery, or "restless" legs. You may feel a strong impulse to kick or thrash your legs. Kicking may occur during sleep and disturb a bed partner throughout the night. The causes of restless legs may include nerve damage or chemical imbalances.

Moderate exercise during the day may help, but exercising a few hours before bedtime can make it worse. People with restless leg syndrome should reduce or avoid caffeine, alcohol, and tobacco; some people also find relief with massages or warm baths. A class of drugs called benzodiazepines, often used to treat insomnia or anxiety, may help as well. These prescription drugs include Klonopin, Librium, Valium, and Halcion. A newer and sometimes more effective therapy is levodopa (Sinemet), a drug used to treat Parkinson's disease.

Sleep disorders may seem unimportant, but they can impair your quality of life. Don't hesitate to raise these problems with your nurse, doctor, or social worker.

Amyloidosis

Dialysis-related amyloidosis (DRA) is common in people who have been on dialysis for more than 5 years. DRA develops when proteins in the blood deposit on joints and tendons, causing pain, stiffness, and fluid in the joints, as is the case with arthritis. Working kidneys filter out these proteins, but dialysis filters are not as effective.